Nationality: United StatesExecutive summary: Co-Discover of the neutrino

American physicist Frederick Reines discovered the neutrino in 1956, collaborating with Clyde Cowan at the Savannah River atomic plant in South Carolina. The existence of the neutrino, an electrically neutral elementary particle having negligible mass moving at nearly the speed of light and interacting very weakly with matter, had been predicted by Wolfgang Pauli in 1930, but until Cowan and Reines' discovery scientists had generally believed that these particles were so infinitesimally small that their existence could not be conclusively proven. Reines shared the 1995 Nobel Prize with the discoverer of the tau lepton, Martin L. Perl.